Added auctex and yasnippets

.emacs.d/snippets/c++-mode/mrg

@@ -0,0 +1,7 @@
+# -*- mode: snippet -*-
+# name: merge
+# key: mrg
+# --
+std::merge(std::begin(${1:container}), std::end($1),
+std::begin($2), std::end($3), std::begin($4));
+$0